1. Field of the Invention
The present invention relates to a suction transport device of a printing plate in which one of printing plates which are accommodated in a magazine is sucked by a suction mechanism, and in this state, the printing plate is taken out from the magazine and transported to a predetermined position.
2. Description of the Related Art
Technology (in the form of printing plate automatic exposure devices and the like) has been developed whereby an image is recorded onto a printing plate (referred to hereinafter as a photopolymer plate). The photopolymer plate is provided with a photosensitive layer (e.g. a photopolymerization layer) on top of a base layer. The image is recorded at the photopolymer plate""s photopolymerization layer with a direct laser beam or the like.
With this sort of technology, images can be recorded onto photopolymer plates quickly. Therefore, sequential feeding of the photopolymer plates is required. For this reason, a plurality of the photopolymer plates, and interleaf sheets for protecting surfaces of the photopolymer plates are alternately accommodated in advance in a magazine in a stacked state. The photopolymer plates and interleaf sheets held in a standby state in predetermined positions are then automatically taken one at a time, by being sucked by a suction mechanism of suckers and fans, and fed into an exposure section.
The magazine accommodating the photopolymer plates therein is also provided with separating plates that correspond to both tip end corner portions of the photopolymer plates accommodated therein. When one of the photopolymer plates is taken out from the magazine by the suction mechanism which includes suckers and fans, these separating plates engage with the photopolymer plate so as to curve the leading end corner portions of this photopolymer plate. Thus, the suctioned photopolymer plate is speedily peeled off from the photopolymer plate that is therebeneath, and taken out.
In a conventional device, because the suction mechanism having suckers and suction fans is disposed fixedly, in a case in which photopolymer plates of a different size are suctioned and taken out, there has been a need to adjust the suckers and the suction fans according to the size of the photopolymer plates.
Also in this case, when the suckers located at the widthwise direction both end portions of the photopolymer plates suck the end portions of the photopolymer plates closer to the end portions of the photopolymer plates (closer to the separating plates), the curvature of the corner portion of the photopolymer plates becomes smaller when the photopolymer plate is curved. Thus, the suckers will have an excellent so-called separability. Therefore, the suckers are preferably provided so as to be positioned at the widthwise direction both end portions of the photopolymer plates. However, if the suckers are disposed fixedly as described above, when an attempt is made to suck, as far as possible, the end portions of the photopolymer plate, it becomes necessary to increase the number of suckers (decreasing the pitch with which the suckers are disposed).
On the other hand, when a photopolymer plate is taken out by the suction mechanism from the magazine, the separating plate which engages with the photopolymer plate and curves the leading end corner portions of the photopolymer plate must curve the tip end corner portions of the photopolymer plate at a fixed curvature. Thus, even with a photopolymer plate of different size, it is desirable that the relative positions of the separating plates and the photopolymer plates correspond at a fixed position.
It is a known fact that when a photopolymer plate is taken out by the suction force of the suckers, the closer to the end portions of the photopolymer plate the suckers are located, the smaller the curvature radius when the photopolymer plate is curved so that separability can improve. However, the optimum dimension (for example, a dimension of the distance between the leading portions of the photopolymer plates and the suckers or a dimension of the distance between the side edges of the photopolymer plate and the suckers) has not yet been established.
In view of the aforementioned facts, an object of the present invention is to provide a suction transport device of a printing plate in which manufacturing cost can be reduced by decreasing the number of suction mechanisms which are needed to take out one of the printing plates which are accommodated in a magazine and in which separability of the printing plates, when the printing plate is taken out, improves, thus improving reliability of the device.
Another object of the present invention is to provide a suction transport device of a printing plate in which a position for sucking the printing plates at which separability is maximized can be clearly established.
In accordance with a first aspect of the present invention, there is provided a suction transport device for use with printing plates, the device comprising: a container in which printing plates are accommodated when the device is used, with the printing plates stacked on top of one another; and a plurality of suction mechanisms disposed at positions opposing the printing plates, along a width direction of the printing plates, at least one of the suction mechanisms being movable in the width direction, wherein the suction mechanisms are operable for removing each printing plate from the container, separately from the other printing plates.
In the suction transport device of the first aspect of the present invention, the printing plates which are accommodated in the container are sucked by the suction mechanisms, and in this state, are taken out from the container, and transported to a predetermined position.
A plurality of suction mechanisms are disposed at positions that oppose the printing plates in the widthwise direction thereof, and at least one of the suction mechanisms located at the widthwise direction of the printing plates can move in the widthwise direction of the printing plates. Accordingly, in a case in which the printing plates of a different size is sucked and taken out, if the movable suction mechanisms can move in accordance with the size of the printing plates, the suction mechanisms can be applied to printing plates of any size.
In this case, in particular, the number of the suction mechanisms is not increased (the pitch at which the suckers and the suction fans are disposed is not decreased). The suction mechanisms can be provided so as to suck portions of the printing plates closer to the widthwise direction end portion thereof by causing the suction mechanisms to move. Also, the curvature of the corner portions of the printing plates is decreased so that a so-called separability relative to the printing plates can improve.
In this way, in the suction transport device of the present invention, the number of the suction mechanisms needed to take the printing plate are reduced so that the reduction of a manufacturing cost can be attained. Separability relative to the printing plates when one of the printing plates is to be taken out improves, thus improving reliability.
In accordance with a second aspect of the present invention, there is provided A suction transport device for use with a plurality of printing plates and interleaf sheets, each printing plate having opposite ends and a leading end corner portion, with each printing plate separated from an adjacent printing plate by an interleaf sheet, the device comprising: a container in which the printing plates and interleaf sheets are placed when the device is used, the container including separation plates disposed movably in a width direction of the printing plates at positions corresponding to leading end corner portions of said printing plates, for aiding in separating an uppermost printing plate in the container from the remaining printing plates of said plurality; and a plurality of suction mechanisms disposed in the width direction of the printing plates at positions opposing the printing plates, with suction mechanisms located along the width direction at either end of the printing plates being disposed movably, and those located in a central vicinity of the width direction of the printing plates being disposed fixedly, the suction mechanisms being operable such that the printing plates and the interleaf sheets are sucked and removed from the container separately from one another.
In the suction transport device of the second aspect of the present invention, when a printing plate is taken out by the suction mechanisms from the container, a pair of plates engage with the printing plate, curve the leading end corner portion of the printing plate, and peel the same. Therefore, separability of the printing plates improves, thus improving reliability.
In this case, since the separating plates can move in the widthwise direction of the printing plates which are accommodated in the magazine, when a printing plate of a different size is to be sucked and taken out, if the separating plates which have been movable in accordance with the size of the printing plate, even with the printing plates of different size, the separating plates and the printing plates can be disposed so as to correspond at a fixed relative position. As a result, the leading end corner portions of the printing plates can always be curved at a fixed curvature so that separability of the printing plates improves more, thus improving reliability.
In the suction transport device of the first or second aspect of the present invention, the suction mechanisms are positioned on the basis of marks.
The positioning of the suction mechanisms after the suction mechanisms have been moved is carried out on the basis of marks. The marks are provided in advance in accordance with the size of the printing plates, thus facilitating the positioning of the suction mechanisms. Further, a corresponding plate size may be specified together with the marks, and the plate size (letters) per se may be used as marks.
Furthermore, the marks are points on the scale disposed along moving tracks of the suction mechanisms. The marks are points on the scale and the amount by which the suction mechanisms are moved can be visually recognized by a T system. That is, it is not necessary to set the marks in accordance with the size of the printing plate each time a moving operation of the suction mechanisms is performed. The suction mechanisms can be moved by an amount corresponding to a difference between a previous size (positions at which the suction mechanisms are now positioned) and a current size (positions at which the suction mechanisms are to be positioned) of the printing plates.
The scale can be always set, or can be set for the suction mechanisms in accordance with moving tracks of the suction mechanisms when needed.